The Jewish mystic Moses de Leon (ca. 1250-1305) is the reputed author of the most important of Jewish mystical books, the "Book of Zohar."

Born in León, Spain, Moses de Leon lived in Guadalajara for the first 30 years of his life, then moved to Ávila, where he spent the remainder of his years. There is little authentic information about his early life, but as a young student he is known to have been attracted to the Cabala, the occult theosophy then flourishing in Provence and Spain.

From 1280 onward, Moses de Leon was circulating copies of the Zohar, stating that he had the original ancient manuscript in his home. The scholar Isaac ben Samuel of Acre visited Spain in 1335 in order to see the original. But by that time Leon was dead, and his widow denied that the book had ever existed. Modern scholars have found...